Wednesday, January 26, 2011

Vladimir Nabokov...the lepidopterist

"Nonfiction: Nabokov Theory on Butterfly Evolution Is Vindicated"


Carl Zimmer

January 25h, 2011

The New York Times

Vladimir Nabokov may be known to most people as the author of classic novels like “Lolita” and “Pale Fire.” But even as he was writing those books, Nabokov had a parallel existence as a self-taught expert on butterflies.

He was the curator of lepidoptera at the Museum of Comparative Zoology at Harvard University, and collected the insects across the United States. He published detailed descriptions of hundreds of species. And in a speculative moment in 1945, he came up with a sweeping hypothesis for the evolution of the butterflies he studied, a group known as the Polyommatus blues. He envisioned them coming to the New World from Asia over millions of years in a series of waves.

Few professional lepidopterists took these ideas seriously during Nabokov’s lifetime. But in the years since his death in 1977, his scientific reputation has grown. And over the past 10 years, a team of scientists has been applying gene-sequencing technology to his hypothesis about how Polyommatus blues evolved. On Tuesday in the Proceedings of the Royal Society of London, they reported that Nabokov was absolutely right.

“It’s really quite a marvel,” said Naomi Pierce of Harvard, a co-author of the paper.

Nabokov inherited his passion for butterflies from his parents. When his father was imprisoned by the Russian authorities for his political activities, the 8-year-old Vladimir brought a butterfly to his cell as a gift. As a teenager, Nabokov went on butterfly-hunting expeditions and carefully described the specimens he caught, imitating the scientific journals he read in his spare time. Had it not been for the Russian Revolution, which forced his family into exile in 1919, Nabokov said that he might have become a full-time lepidopterist.

In his European exile, Nabokov visited butterfly collections in museums. He used the proceeds of his second novel, “King, Queen, Knave,” to finance an expedition to the Pyrenees, where he and his wife, Vera, netted over a hundred species. The rise of the Nazis drove Nabokov into exile once more in 1940, this time to the United States. It was there that Nabokov found his greatest fame as a novelist. It was also there that he delved deepest into the science of butterflies.

Nabokov spent much of the 1940s dissecting a confusing group of species called Polyommatus blues. He developed forward-thinking ways to classify the butterflies based on differences in their genitalia. He argued that what were thought to be closely related species were actually only distantly related.

At the end of a 1945 paper on the group, he mused on how they had evolved. He speculated that they originated in Asia, moved over the Bering Strait, and moved south all the way to Chile.

Allowing himself a few literary flourishes, Nabokov invited his readers to imagine “a modern taxonomist straddling a Wellsian time machine.” Going back millions of years, he would end up at a time when only Asian forms of the butterflies existed. Then, moving forward again, the taxonomist would see five waves of butterflies arriving in the New World.

Nabokov conceded that the thought of butterflies making a trip from Siberia to Alaska and then all the way down into South America might sound far-fetched. But it made more sense to him than an unknown land bridge spanning the Pacific. “I find it easier to give a friendly little push to some of the forms and hang my distributional horseshoes on the nail of Nome rather than postulate transoceanic land-bridges in other parts of the world,” he wrote.

When “Lolita” made Nabokov a star in 1958, journalists were delighted to discover his hidden life as a butterfly expert. A famous photograph of Nabokov that appeared in The Saturday Evening Post when he was 66 is from a butterfly’s perspective. The looming Russian author swings a net with rapt concentration. But despite the fact that he was the best-known butterfly expert of his day and a Harvard museum curator, other lepidopterists considered Nabokov a dutiful but undistinguished researcher. He could describe details well, they granted, but did not produce scientifically important ideas.

Only in the 1990s did a team of scientists systematically review his work and recognize the strength of his classifications. Dr. Pierce, who became a Harvard biology professor and curator of lepidoptera in 1990, began looking closely at Nabokov’s work while preparing an exhibit to celebrate his 100th birthday in 1999. She was captivated by his idea of butterflies coming from Asia. “It was an amazing, bold hypothesis,” she said. “And I thought, ‘Oh, my God, we could test this.’ ”

To do so, she would need to reconstruct the evolutionary tree of blues, and estimate when the branches split. It would have been impossible for Nabokov to do such a study on the anatomy of butterflies alone. Dr. Pierce would need their DNA, which could provide more detail about their evolutionary history.

Working with American and European lepidopterists, Dr. Pierce organized four separate expeditions into the Andes in search of blues. Back at her lab at Harvard, she and her colleagues sequenced the genes of the butterflies and used a computer to calculate the most likely relationships between them. They also compared the number of mutations each species had acquired to determine how long ago they had diverged from one another.

There were several plausible hypotheses for how the butterflies might have evolved. They might have evolved in the Amazon, with the rising Andes fragmenting their populations. If that were true, the species would be closely related to one another.

But that is not what Dr. Pierce found. Instead, she and her colleagues found that the New World species shared a common ancestor that lived about 10 million years ago. But many New World species were more closely related to Old World butterflies than to their neighbors. Dr. Pierce and her colleagues concluded that five waves of butterflies came from Asia to the New World — just as Nabokov had speculated.

“By God, he got every one right,” Dr. Pierce said. “I couldn’t get over it — I was blown away.”

Dr. Pierce and her colleagues also investigated Nabokov’s idea that the butterflies had come over the Bering Strait. The land surrounding the strait was relatively warm 10 million years ago, and has been chilling steadily ever since. Dr. Pierce and her colleagues found that the first lineage of Polyommatus blues that made the journey could survive a temperature range that matched the Bering climate of 10 million years ago. The lineages that came later are more cold-hardy, each with a temperature range matching the falling temperatures.

Nabokov’s taxonomic horseshoes turn out to belong in Nome after all.

"What a great paper," said James Mallet, an expert on butterfly evolution at University College London. "It's a fitting tribute to the great man to see that the most modern methods that technology can deliver now largely support his systematic arrangement."

Dr. Pierce says she believes Nabokov would have been greatly pleased to be so vindicated, and points to one of his most famous poems, “On Discovering a Butterfly.” The 1943 poem begins:

I found it and I named it, being versed

in taxonomic Latin; thus became

godfather to an insect and its first

describer — and I want no other fame.

“He felt that his scientific work was standing for all time, and that he was just a player in a much bigger enterprise,” said Dr. Pierce. “He was not known as a scientist, but this certainly indicates to me that he knew what it’s all about.”

This article has been revised to reflect the following correction:

Correction: January 26, 2011

An earlier version of this article misstated the year Vladimir Nabokov immigrated to the United States. It was 1940, not 1941.

"Nabokov’s Blue Butterflies"


Erin Overbey

January 27th, 2011

The New Yorker

Vladimir Nabokov once said, “A writer should have the precision of a poet and the imagination of a scientist.” The famed author exhibited both equally in his writing and in his non-literary pursuits, which included lepidopterology, the study of butterflies and moths. Although he is of course best known for his intricate novels and essays, the past decade has seen a rediscovery of Nabokov’s entomological ventures. On Tuesday, the Times revealed that a team a scientists had vindicated a nearly seventy-year-old theory of his about the development of the Polyommatus blue butterflies:

[I]n a speculative moment in 1945, [Nabokov] came up with a sweeping hypothesis for the evolution of the butterflies he studied, a group known as the Polyommatus blues. He envisioned them coming to the New World from Asia over millions of years in a series of waves. Few professional lepidopterists took these ideas seriously during Nabokov’s lifetime. But in the years since his death in 1977, his scientific reputation has grown. And over the past 10 years, a team of scientists has been applying gene-sequencing technology to his hypothesis about how Polyommatus blues evolved. On Tuesday in the Proceedings of the Royal Society of London, they reported that Nabokov was absolutely right.

Dr. Naomi Pierce, a co-author of the report, organized four separate trips to the Andes to collect the blues, and then she and her colleagues at Harvard sequenced the genes of the butterflies, as well as comparing the number of mutations each species had acquired. Their research resulted in the revelation that five waves of butterflies came from Asia to America, as Nabokov had originally hypothized.

Butterfly hunting was a popular sport among Russian intellectuals in the early- to mid-twentieth century, and enthusiasts were often referred to as “fly doctors.” Nabokov became fascinated with butterfly collecting and study as a child, and, when he emigrated to America in 1941, he brought his love of lepidoptology with him, taking a job as a curator at the Museum of Comparative Zoology at Harvard University. In an interview he gave to the Paris Review in 1967, Nabokov noted that

The pleasures and rewards of literary inspiration are nothing beside the rapture of discovering a new organ under the microscope or an undescribed species on a mountainside in Iran or Peru. It is not improbable that had there been no revolution in Russia, I would have devoted myself entirely to lepidopterology and never written any novels at all.

The novelist also went on extensive butterfly-hunting expeditions across America while he was working on his masterpiece, “Lolita.” In “Nabokov’s Blues: The Scientific Odyssey of a Literary Genius,” Kurt Johnson and Steven L. Coates observe,

The sublime joy associated with this [entomological] work was due to the butterfly-hunting trips to the West that Nabokov took every summer. Nabokov, who never learned to drive a car, estimated that in the glory years between 1949 and 59, VĂ©ra drove him more than 150,000 miles all over North America, mostly on butterfly trips. Those expeditions have taken on the aura of legend among lepidopterists as well as Nabokov’s literary admirers, and it was a habit he maintained, with only the geographical scenes shifting, for the rest of his life.

Blue butterflies can have some of the shortest life spans of any species, and Nabokov seemed particularly fascinated by this quality of ephemeral metamorphosis. In “Speak, Memory,” part of which ran as an essay titled “Butterflies” in the June 12, 1948, issue of The New Yorker, he contemplated the connection between art and the changing subtlety of these fragile insects:

The mysteries of mimicry had a special attraction for me. Its phenomena showed an artistic perfection usually associated with man-wrought things. Such was the imitation of oozing poison by bubble-like macules on a wing (complete with pseudo-refraction) or by glossy yellow knobs on a chrysalis (“Don’t eat me—I have already been squashed, sampled, and rejected”). When a certain moth resembled a certain wasp in shape and color, it also walked and moved its antennae in a waspish, unmothlike manner. When a butterfly had to look like a leaf, not only were all the details of a leaf beautifully rendered but markings mimicking grub-bored holes were generously thrown in. “Natural selection,” in the Darwinian sense, could not explain the miraculous coincidence of imitative aspect and imitative behavior, nor could one appeal to the theory of “the struggle for life” when a protective device was carried to a point of mimetic subtlety, exuberance, and luxury far in excess of a predator’s power of appreciation. I discovered in nature the nonutilitarian delights that I sought in art. Both were a form of magic, both were a game of intricate enchantment and deception.

Nabokov’s love of and appreciation for entomology would continue until his last days. Shortly before he passed, in 1977, his son Dimitri recorded the following anecdote in his diary:

A few days before he died there was a moment I remember with special clarity. During the penultimate farewell, after I had kissed his still-warm forehead—as I had for years when saying goodbye—tears suddenly welled in Father’s eyes. I asked him why. He replied that certain butterfly was already on the wing; and his eyes told me he no longer hoped that he would live to pursue it again.

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